TREATMENT OF MATERIAL IN THE FIELD 

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Northern Kalahari Northern Kalahari Tree and Bush Savanna (de Beer, M. S.) (Plate 9).

This sector covers the remainder of the Kalahari west of the bounderies of the Eastern Sector. It is bordered in the north-east by the belt of woodland south of the Makgadikgadi, in the central sector by the woodland south of the Botletle River, and, in the west, extends into the southern part of Ngamiland to about 20°30′ S. latitude on the South West African border. The Ghanzi Farms are excluded as they are atypical. The vegetational association of this sector extends across the Botletle River and covers the main portion of the North-eastern Sector to about 19° S. but here, takes on a slightly different form from that found south of the Makgadikgadi (see North-eastern Sector).
In the east this association continues through to the Transvaal border between about Mochudi and Debeeti (see Eastern Sector). The association takes the form of open T. sericea scrub, on sandy ground, in favourable scattered localities, the T. sericea growing to medium-sized trees up to 10 ft. high but always forming a very open association. Camelthorn, A. giraffae, is less in evidence, the trees generally smaller than they are in the south-west, except in favourable localities. Other scrub trees occurring include Burkea africana, Peltophorum africanum, Boscia albitrunca, Croton sp., Rhus sp., Combretum sp., Z. mucronata, with the following shrubs Croton sp., Grewia fiava, Grewia spp., A. detinens, and other species of Acacia, Bauhinia sp. and Commiphora sp.
There is much open grassland, often with scattered solitary trees and bushes and a great deal of bare sandy ground. The open pans, characteristic of the remainder of the Kalahari, are few and far between and never so well developed, usually having a grassed surface (Mashoro Pan), although there are exceptions to this, as for example the pan at Lephepe, which is, however, small and insignificant compared with most of these in the south. A feature of the northern part of the Kalahari is a series of dry depressions or fossil drainage lines most of which lie roughly west to east. The Okwa runs from the South West Mrican border at c. 22°25′ S. east to c. 24° E., then north-east in the direction of Lake Dow. This is joined at about 24° E. by a further depression running from south to north. The Buitsivango (Hanahai) depression enters Botswana about 22° S., 21° E. on the South West African border to run south-eastwards joining the Okwa. North of the Okwa, the Deception Depression, rising in the Ghanzi Farms, leads east, again to about 24° E., then northeast towards Rakops on the Botletle River. Passarge, north of Deception, is well demarcated between 23° E. and 24° E., disappearing near the junction of the Kuki-Makalamabedi fence. A further depression lies parallel and immediately east of the eastern boundary of the Central Kalahari Game Reserve in the direction of Lake Dow but disappearing about 22° S. These depressions carry better developed woodland than the surrounding country. In the case of the Okwa Depression this woodland forms a belt along it, to a depth, in places, of up to 12 miles (Campbell, pers. comm.). At the western end of Deception (Van Zyl’s Cutting) there are huge camelthorn A. giraffae and leadwood, Combretum imberbe, trees, which Roberts. (1935) compares favourably with ‘the scrawny trees of the central Kalahari’. The Buitsivango (Hanahai) and Passarge Depressions carry similar belts of woodland.
Roberts (1935) reports seeing a night ape, Galag(J senegalensis, at Damara Pan and a specimen was collected in the Hanahai not far from Damara Pan.
These records are isolated, being far from their nearest limits of distribution, and point to the desirability of further investigation of those depressions in which this and other woodland species may eventually be shown to occur.

Methods and Techniques Planning

As the study area was very large, it was recognized that as full a cover as might be desired could not be given in the time available. In order to ensure that the main ecosystems would each be sampled to the fullest extent possible, the study area was divided into six sectors, one or more of which included representative samples of these ecosystems (Map iv, p. 13).
Within each of these sectors it was planned to establish a series of collecting stations, visiting each at least once in the dry and once in the wet season. In the main this aim was achieved, although the same stations were not always used on subsequent visits where it was found, through experience, that others offered a more representative sample of the ecosystem involved.
In a territory that is largely waterless and sparsely inhabited, forethought in providing for the food and water supplies for the parties, involving two or three Europeans and five to seven African staff, was essential if they were to operate efficiently. During an avifaunal survey (Smithers, 1964) Landrovers were found to be ideal for use both on the tracks and off them and equally useful in the present work, especially for night observation and hunting
Their capacity, however, was inadequate to carry the larger parties, together with their personal kit, equipment and sufficient fuel and water, to support them for a reasonable working period. In certain parts of the country where there was relatively hard ground, as, for example, in the eastern sector and round the Okavango in the dry season, it was possible to use a two-wheel-drive 5-ton Bedford truck. During . the wet season in the Okavango, where muddy tracks were a problem, and in others where the sand was soft, it could only be used with difficulty, in conjunction with the Landrover fitted with the heavy-duty winch, which was in frequent use in pulling the heavier vehicle out of difficulties. Originally it was hoped that a four-wheel-drive 5-ton vehicle might be made available, which then could have been used anywhere, but funds for its purchase were not available.
As a compromise a 1 -1-ton Ford four-wheel-drive truck was later provided which served the purpose well, although limited in carrying capacity compared with the 5-tonner. ,When the 5-tonner was used, large ventilated collecting boxes were carried, 1·5 m long X 1 m broad X 0·7 m high, either fitted with five trays with soft fibre bottoms, on. which specimens could be pinned and in which they could remain. until dry, or witl~ trays with expanded metal bottoms in which larger skins, after salting, could be left to dry. Material handled in these containers returned in far better condition than when carried in other ways. With the use of the smaller I1-ton Ford smaller containers had to be used.
In the Kalahari, fuel dumps had to be organized in advance of visits, the available space on the 5 tonner being used to carry water supplies. In order to achieve the maximum coverage of the study area the Smithsonian teams and the main party were routed to areas not already being dealt with by members of the Botswana Department of Wildlife and National Parks and other associates. From the outset it was recognized that, in order to fulfil the objects of the survey, much more information was required on the individual specimen than had generally been the practice to record in the past. Material already in Museum collections, while providing useful morphological and distributional data, lacked information on habitat, habits, food or reproduction, all of which was considered to be among the priorities in the knowledge required for the better understanding of the species. Again, in anticipation that teams and individuals would be working independently, it was necessary to devise a system whereby they were constantly reminded of the type of information required and given a means of presenting this in a standard form. To this end printed record forms were designed on which were set out an itemized list of the types of data which it was mandatory on participants to record (Smithers, 1967) (Fig. 1).
These forms, printed on the best quality paper, so as to withstand the rigours of use in the field, were carried in heavy-duty loose-leaf folders and at the conclusion of each stage of the field-work were filed under the name of the species. This greatly facilitated the recovery of data.
In addition a cyclostyled set of instructions was provided, elaborating on the methods to be used and the materials to be employed in processing and preparation of the specimens. Participants used a serial numbering system, each number prefixed by his initials or a letter or letters assigned to him. The main party used the prefix BP. Each specimen collected was given a prefixed serial number, which was recorded on the appropriate section on the form, and the same prefix and number were applied to each of the parts of the specimen retained, such as the skin, skull, stomach contents, reproductive tract or other organs or the ecto- or endoparasites preserved.
In addition to the data, which have traditionally been applied to Museum material, sex, date and locality, the forms drew attention to the necessity of recording four measurements, five in the case of Chiroptera; the weight; the state of the mammae, indicating whether a female was lactating or dry; its reproductive status and if gravid, how many foetuses, whether implanted in the left or right uterine horns, and their measurements and weights. In males the position of the testes, whether abdominal or scrotal, and their weight as a pair were recorded. Spaces were provided for notes on the habitat in which the specimen was taken, a record of the stomach contents and a section for general notes such as the manner in which the specimen was taken, either trapped or shot, when it was taken, the type of baits used, the size of the herd from which it was taken, and any other information which might contribute to a knowledge of the species concerned. Trapping Trap-lines for rodents consisted of a unit of 60 ‘Museum Special’ breakback traps, this being a convenient number to carry in one of the standard canvas carrying-bags. Normally 120 traps were set by each operator although, in exceptional cases, where the operator was not engaged in other duties at the time, up to 300 traps. These bags were equipped with a smaller canvas bag for the markers and another for the bait. Markers consisted of 12 X 6-cm luggage abels, sprayed with a bright scarlet or orange lacquer, with a loop of medium-weight string for attachment to a convenient high point adjacent to each trap set. The lines were set roughly in a straight line or a curve leading eventually back towards camp. The distances between the individual traps varied but the aim was that the marker of the next trap could be seen from the one before. This was important as the lines were visited after dark.
Where rodent activity was obvious, several traps were set close to each other, but otherwise they were laid without regard for this, usually under the cover of a bush or tuft of grass but often completely in the open. In woodland associations special groups of traps were set on the thicker branches or trunks of trees, or attached to the trunk itself with a nail through a hole bored in one end. These were useful for arboreal species such as Thallomys paedulcus and Graphiurus murinus, although not as effective as shooting with a ·22 or a ·410 and just after dark when the rodents were picked up in a dazzling light as they moved in the trees.
A wide variety of baits were used including peanuts, bread, pastes of rolled oats, mealie-meal and oatmeal with peanut butter, fish oil, or the liquid from tinned meats and vegetables. One of the best all-round bait was rolled oats made into a paste with ‘Purity’ baby food, marrowfat and peas. Paste baits, while convenient to use and quick to apply, were particularly susceptible to being carried off by ants and, where these were troublesome, peanuts or vegetable marrow-pips were used as they remained longer on the trigger. In areas where there were likely to be shrews, Crocidura sp., or where they appeared in the traps, some traps were set baited with rodent meat. ‘Museum Special’ traps are on the light side for species such as Otomys angoniensis or Dasymys incomtus and in areas where they were present No.4 breakbacks were also employed, one side of the spring being unhooked so as to soften up the blow and so avoid damage to the specimen. Trap losses can be high through small predators, attracted by the catch, carrying this off along with the trap. Vervet monkeys and baboons were also troublesome in some areas and herds of wildebeest and buffalo also caused high trap losses through walking on them. Cattle seemed to be attracted by the markers and frequently chewed them off the bushes. In the early stages steel gin-traps were used for small predators but soon discarded as they damaged* the specimens and caused hardship. Single-gated, folding, live traps of sizes 25 X 20 X 80 cm and 23 X 23 X 66 cm were substituted and proved effective and useful for small predators such as the slender mongoose and genets. These were normally baited with doves or the carcasses of small mammals such as rodents, hares, squirrels, or the intestines of larger species. Their efficacy was greatly enhanced if the body of the trap was hidden under cover or disguised by covering it with handfuls of grass or twigs, the gate only left free. It was also important to ensure, by means of piles of twigs, that access was not available to the end of the trap in which the bait was lying, thus forcing access to it via the open gate. Mole rats were taken with ‘Macabee’ traps. Locating a line of heaps a fresh ‘throw’ was chosen where the subsoil pushed up by the animal still showed the form of the hole. A hole was dug at the site of the heap about 45 cm square to such a depth that the two holes leading to the heap were revealed. A pair of ‘Macabees’ joined together with a fine wire were set, one in each hole. Sometimes catches were made with this method within a few minutes although, occasionally, a much longer time elapsed before the mole rat came to investigate the disturbance caused by the opening.
It became the practice to carry a few pairs of ‘Macabees’ in the cab of the vehicle and, by arranging to stop where ‘heaps’ were in evidence, to secure specimens during tea and lunch stops. Various types of home-made live traps were also employed for Murids which were useful in securing live specimens for study.

Night-hunting

The great majority of the predators collected, and indeed specimens of many other species as well, were taken with the aid of dazzling lights at night. The Landrover was equipped with a high-power spotlight on a lead long enough to allow of its use from the top of the cab. Two operators were settled on the top, one with the spotlight, the other with a 12-bore shotgun and a headlamp. Specimens located by the reflection from the eyes were taken, either directly from the cab, while held in the beam of the spotlight or, if out of range, the hunter would climb off the vehicle and follow up with the headlight, the spotlight and cab lights in the vehicle being temporarily shut off to avoid his movement being observed against a lighted background. The headlamps were also used for excursions from camp on foot.
These methods proved quick, efficient, selective and humane for collection specimens and at the same time gave a quick means of visually recording nocturnal and other species occurring in an area, many of which are otherwise extremely diffi:ult to locate.
For night-hunting a double-barrelled or repeating, well-choked, 12-bore shotgun was used with No.6 (British) shot or AAA for heavier species. Light rifles ( . 222) with telescopic sights were used effectively by some operators but, in general, the shotgun was found to be the best all-round weapon and is certainly safer at night when dealing with species up to the size of a leopard.
Baits in the form of the carcasses of large species were used on occasion but a more effective manner of attracting predatory species over a broader area, was the dragging of baits late in the afternoon or on the outward journey during night observation or hunting. Intestines were frequently employed for this purpose and proved very effective.

The Record Forms

The data appertaining to each specimen collected was recorded on a form 22 X 14 cm on which were printed a series of headings against which the appropriate data were entered (fig. i).

ABSTRACT 
INTRODUCTION 
ACKNOWLEDGEMENTS
THE STUDY AREA 
Political
Size and location
General
Topography
Rainfall
Description of subdivisions used .,
Eastern sector
North-eastern sector
Makgadikgadi Pan
Okavango delta
North-western sector
Kalahari. .
GAZETTEER . .
METHODS AND TECHNIQUES 
Planning ..
Trapping  »
Night hunting
The record forms
Collector’s name and specimen number
Sex… ..
Date
Locality. .
Measurements and Weights
Mammae
Habitat. .
Stomach contents. .
Reproductive tracts and testes ..
Notes
TREATMENT OF MATERIAL IN THE FIELD 
CLASSIFICATION
CHECK LIST
LIST OF SPECIES NOT RECORDED BUT WHICH MAY OCCUR
BIBLIOGRAPHY 
INDICES 
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